Stud

ABSTRACT

A fastener or the like is secured to a thin panel having a blind hole between its surfaces. The fastener or the like includes a head and a shank, the head including a first annular flange and a second annular flange of smaller radial extent than said first annular flange and defining with said first annular flange an undercut groove into which panel material is displaced by the first annular flange upon assembly to the panel sheet. The blind hole has an open end portion large enough to receive the second annular flange and has its opposite end portion closed by a part of the panel. The head has a recess juxtaposed with the part of said sheeted material closing the blind hole.

' United States Patent lnventor Richard B. Ernest Richboro, Pa. Appl. No. 817,620 Filed Apr. 16, 1969 Patented Jan. 19, 1971 Assignee Penn Engineering & Manufacturing Corporation Danboro(Doylestown), Pa. in corporation of Delaware STUD 13 Claims, 10 Drawing Figs.

0.8. CI..,........ Isl/41.73, 29/432 Int. Ch, F16b 39/00 Field ofSearch 151 41.73, 41.72, 41.74, 41.7; 85/1K, 9, IP; 287/203, 20, t 20.5; 52/707; 85/45; 29/432, 505

References Cited UNITED STATES PATENTS 3,270,355 9/1966 Tildesley V l5l/4l.73)1

Primary Examiner-Ramon S. Britts t fp v ya q Perr l ABSTRACT: A fastener or the like is secured to a thin panel having a blind hole between its surfaces. The fastener or the like includes a head and a shank, the head including a first annular flange and a second annular flange of smaller radial extent than said first annular flange and defining with said first annular flange an undercut groove into which panel material is displaced by the first annular flange upon assembly to the panel sheet. The blind hole has an open end portion large enough to receive the second annular flange and has its opposite end portion closed by a part of the panel. The head has a recess juxtaposed with the part of said sheeted material closing the blind hole.

PAIEN1E-n-Jmsmn. 3.55 61 9 sum z'nrz INVENT R RD B. ERNEST 15 AT TURNEYS srun r BACKGROUND or TusiNvEnrioN As is known, fasteners or thelike, such as studs andsolderthe coating, etc. be not pierced or otherwise marred. Also, at

times the appurtenances on the front surface of the panel, or

the use to which the panel is to be put, will not accommodate or permit bolt heads or holes through the panel.

In the foregoing instances a concealed head fastener is often used, the concealedhead fastener having a head imbedded in r the thin panel by first providing ablind; hole in the back surface of the panel and then insertingthe head of the fastener into thefhol'e, the head being then squeezed intothe panel until it is'flush with the back surface of the panel.

Due to the factthat such ,panels may be as thin asfone-sixv teenth or threejthirty-seconds of an inch, it'is seen that after the blind hole is bored in the panel yery little panel material remains between the bottom surfaceof the hole and the front surface ofthepanel.

o d of the fastener a slightprojection on it, or if the borehas notbeenformedwith a completely flat bottom surface, since the clearance between the end face of the Thus, if thehe head and the bottom surface of the blind hole is very small, it

is possible that whenthe fastener is sque'ezed'into place the projection on the fastener, or on the bottom surface of the blindhole,' niay be pushed by the head through the front surface of thepanel, and thus that the front surface of the panel.

The fastener described hereinafter tends to substantially reduce the likelihood that the heretofore described marring of the front surface of the panel will take place.

BRIEF SUMMARY OF THE INVENTION Since the marring of the from surface of the panel'has essentially taken place previously because of the possible contact between projections extending from juxtaposed substantially flat surfaces, namely, the end face of thehead of the fastener and the bottom surface of the blind hole, it is proposed to makethe end face of the head of the fastener recessedand concave so that any projection extending from the bottom surface of the blind hole will extend into the recess without contacting the fastener after the fastener is secured to thepanel."",, Q a

The foregoing and other objects of this invention, the principles of this invention andthe best modes in which I have contemplated applying such principles will more fully appear from the following description and accompanying drawings in illustration thereof. r

BRIEF DESCRIPTION OF THE VIEWS of a fastener or stud constructed in accordance with the present invention,the view being taken along the line 1-1 in FIG.2; 1

FIG. 2 is a top view of the fastener shown in FIG. 1;

FIG. 3 is a side elevation of the fastener shownin FIGS. 1 and 2, showing the fastener placed upon a panel and prior to the'fastener being-secured to the panel, the anvil and punch used in securing the fastener to the panel being also illus- FIG. 4 is a cross-sectional view-of the fastener and panel showing the fastener and panel secured to each other;

FIG. 5 is a partial, side elevation view of a prior art fastener, showing it about to be secured to a panel, the fastener in FIG. 55 having no recess in the end surface of the pilot facing the bottom surface of the blind hole in the panel;

FIG. 6 is an enlarged, cross-sectional view of another embodiment of a stud constructed in accordance with this invention;

' FIG. 7-is a top viewof the stud shown in FIG. 6;

FIG. Q is a side elevation of a further embodiment showing this invention incorporated in a terminal;

' FIG. 9 is a bottom view of the terminal shown in FIG. 8; and FIG. 10 is a top view of the terminal shown in FIGS. 8 and 9.

I DETAILEDDESCRIITION.

. Referring to the drawings, FIG. ll'illustrates a self-clinching fastener or stud 10 having a head 12 and a depending integral shank 14, the shank 14 being provided with threads 16 adapted to receive a nut or the like. j, n

The head 12 is formed by a first'annular flange 18, generally circular as shown in FIG. 2, and having its outer peripheral surface knurled, as indicated at 20, in an annular array extending fully around theflange 18 to provide a means tending to resist rotation of the fastener 10 after it is imbedded in a sheeted material or panel 22, FIGS. 3 and 4, Le, to tend to resist torque forces imposed upon the fastener after it is secured to the panel 22. r 1 The head 12 also includes a second annular flange or pilot 24 which extends radially outwardly less than the knurled flange 118, as shown, and which has an inclined, undercut surface 26 which together with the generally horizontal (as illustrated?- surface .28 of the knurledflange 24 define an annular "groove 30 into which sheeted material 22, FIG 4, is forced to 38, as shown, although it will be seen that the well 32 could be of another shape. I n

,The sheeted material or panel, 22 is provided with a blind hole or-bore 40 between its two surfaces 42 and 44, as shown in FIGS. 3 and 4..The hole 40 is open at its upper end, as viewed in the drawings, and in communication with the surface 42, but at its opposite end the hole 40 is closed by the relativelythin wall 46which defines, in part, the surface 44.

As shown, the hole 40 is square shouldered and has a flat, horizontal (as viewed in the drawings) surface 48 which must be slightly spaced fromthe'flat end face 34 of the head 12 after the headis fully secured to the sheeted material or panel 22 to insure that the knurled flange will be fully imbedded.

To secure the fastener 10 to the panel 22, the panel 22 is preferably counterbored to provide a hole a few thousandths of an inch larger in diameterthan the outside diameter of the pilot 24and at least a few thousandths of an inch deeper than the distance between surfaces 66 and 34. The panel 22 is then placed upon a suitable anvil 60 and the fastener 10 is placed upon the panel 22 with the pilot 24 extending into the hole 40 and the knurled flange 18 resting upon the surface 42 of the panel 22. Thereafter a suitable punch 62, having a sufficiently large bore 68, as shown in FIG., 3, is: placed over the shank 14 with the face 64 of the punch resting, upon the surface 18.

A sufficient force is then applied to the punch 62 to squeeze the knurled flange 18 into the panel 22 adjacent the panel sur' face 42 at which time the panel material adjacent the flange if; is displaced by it downwardly and radially inwardly into the annular undercut groove 30 to provide a tight connection between the panel 22 and the head 12.

Since the punch face 64 overhangs the knurled flange 18, the head 12 is driven into the panel only until the surface 66, FIG. 4, of the flange 18 becomes flush with the panel surface 42.

when the knurled flange 18 is driven flush with the upper surface 42 of the panel 22, the end face 34 ofthe pilot 24 is I slightly spaced from the bottom surface 48 of the hole 40, by a few thousandths of an inch, as shown in FIG. 4, in enlarged form, since the hole 40 is made a few thousandths of an inch deeper than the thickness of the head 12 between the surfaces 34 and 66, as indicated previously.

it will be understood that the drawings illustrate the various parts greatly enlarged as the thickness of the panel 22 between front or under surface 44 and the back or upper surface 2 may be as thin as one-sixteenth of an inch. Also, it will be understood that by providing a central, concave recess or well 32 in the pilot 24, the outer peripheral portion of the pilot 24 between the flange l8 and the end face 34 remains of the same thickness as heretofore, so that it is fully available to form, with the knurled flange 18, a circular groove 30 which is concentric with the well 32.

Further, the well 32 may extend into the head l2 a variable amount, as desired.

While the bore 40 has been described as square shouldered it will be seen that the shoulders thereof could also be radiused depending on the clearances and the shape of the pilot 24. To facilitate entry of the pilot 24 into the bore 40, the pilot 24 is provided with a radiused corner, as shown.

The flange 18 has been described as knurled for the purpose of tending to resist torque forces imposed on the fastener after it is secured to the panel.

The invention has been described primarily in terms of a threaded stud but it is seen that if merely a cylindrical shank is provided, the fastener could be used as a guide pinlike element, but this is not illustrated.

FIG. illustrates a fastener 100 in which the pilot 102 of the head 104 is constructed in accordance with the prior art. The pilot m2 has no recess or well (such as the well 32 shown in PEG. 1 for the fastener and, hence, in FIG. 5 the end face 3.06 extends across the entire pilot 102. It was found that during the manufacture of such fasteners, a central teat, such as the teat 110 shown in FIG. 5, would sometimes remain on the pilot 102 and would project outwardly from the end face 106. Also, it was found that the hole 112 in the sheeted material or panel 1114 might not be provided with a completely fiat bottom surface H6 and at times the surface U6 would have an upstanding central teat 118 extending toward the pilot 102.

if the fastener 110% has ateat lllltl and/or the panel 114 has a teat 1H8, since the clearance between the pilot and face 106 and the bottom hole surface l 16 is limited to a few thousandths of an inch, the assembly of such fasteners Hill and panels 1M by the anvil 122. and punch 124 (partially shown) resulted in the panel front or under surface 126 being damaged or marred as the teats llltl and M8 tended to belly the surface 126 or to penetrate it.

Thus, it is seen that by providing aclinch-type fastener with a well or concave recess in its pilot, the likelihood of marring or damaging the front or under surface of the panel is substan tially reduced or eliminated.

FIGS. 6 and 7 illustrate another embodiment ol :1 selfclinching fastener or stud 200 constructed in accordance with this invention. The stud 200 has a head 202 and a depending integral shank 2%, the shank 204 being provided with threads 206 adapted to receive a nut or the like.

The head 202 is formed by a first annular flange 208 of hexagon shape, as shown in FIG. 7, to provide a means tending to resist rotation of the stud 2% after it is imbedded in a sheeted material or panel.

The head 202 also includes a second annular flange or pilot 2110 which extends radially outwardly less than the hexagon flange 26!}, as shown, and which has an inclined, undercut surface 214 which together with the generally horizontal (as illustrated) surface 212 of the hexagon flange 208 define an annula: groove 216 into which sheeted material is forced to flow by the hexagon flange 203 when the stud 200 is secured to the sheeted material.

The pilot 210 is provided with a recess or well 213, similar to the well 32 shown in connection with FIGS. 1 to 4, the well 218 being substantially centrally located, as shown, and communicating with the generally flat end face 220 of the pilot. The well 218 may be defined by a part-conical wall 222 and a generally flat end wall 22d, as shown, although it will be seen that the well 218 could be of another shape.

FIGS. 8, 9 and 10 illustrate this invention incorporated in a terminal to which electrical wires or the like may be attached or soldered. Referring to FIGS. 8, 9 and 10 a terminal 300 is illustrated having a head 302 and a depending integral shank 304, the shank 304 being provided with an elongated, open ended slot 306.

The head 302 is formed by a first circular flange 308 which is to be imbedded in a sheeted material or panel.

The head 302 also includes a secondannular flange or pilot 310 which extends radially outwardly less than the circular flange 308, as shown, and which with the flange 308 defines an undercut groove 312 into which sheeted material is forced to flow by the circular flange 308 when the fastener 10 is secured to the sheeted material.

The pilot 310 is provided with a recess or well 318, substantially centrally located, as shown, and similar to the wells 32 and 218 described in connection with the previous embodiments.

I claim:

1. In combination:

a sheeted material or panel having first and second surfaces and a blind hole between said first and second surfaces;

a fastener or the like including an axially rigid and. shank;

said head including a first annular flange;

said head including a second annular flange of smaller radial extent than said first annular flange and defining with said first annular flange an undercut annular groove into which sheeted material is displaced by said first annular flange upon assembly to said sheeted material;

said blind hole having an open end portion large enough to receive said second flange and having its opposite end portion closed by a part of said sheeted material to define a substantially planar closed end; and

said head having a central recess juxtaposed with the part of said sheeted material closing said blind hole, thickness of said sheet material being only slightly greater than the axial extent of said head.

2. The structure set forth in claim ll wherein said first amidlar flange includes means tending to resist rotation of said fastener.

3. The structure recited in claim ll wherein said shank li threaded.

The structure recited in claim 1 wherein said Shani J. is slotted.

S. The structure recited in claim 2 wherein said means is :2, knurl.

6. The structure recited in claim 2; wherein said means comprises forming said first annular flange of noneircular shape.

7. In combination:

a thin sheeted material or panel having. first and second surfaces and a blind hole between said first and second surfaces;

a fastener or the like including an axially rigid head and a shank;

said head including an annular flange;

said head including an annular pilot of smaller radial extent than said annular flange and defining with said annular flange an annular undercut groove into which sheeted material is displaced by said annular flange upon assembly to said sheeted material;

said blind hole having an open end portion large enough to receive said pilot and having its opposite end portion closed by a thin part of said sheeted material;

said head having a central recess juxtaposed with part of said sheeted material closing said blind hole;

the thickness of said sheeted material being only slightly greater than the axial extent of said head;

said annular flange including knurls on its outer periphery tending to resist rotation of said fastener; and

said shank being threaded.

8. A one-piece clinch-type fastener adapted to be secured to thin panels comprising:

an axially rigid head and an externally threaded shank being solid in transverse cross section;

said head including a first annular flange;

said head including a second annular flange;

said first annular flange being between said second annular flange and said shank;

said second annular flange being of smaller radial extent than-said first annular flange and defining with said first annular flange an undercut annular groove to receive panel material displaced by said head during assembly of said fastener to a panel and said second annular flange having a centrally recessed end face on the side of said head opposite said shank.

9. The structure set forth in claim 8 wherein said first annular flange includes means tending to resist rotation of said fastener.

10. The structure recited in claim 9 wherein said means is a knurl,

11. The structure recited in claim 9 wherein said means is of noncircular shape.

12. A one-piece clinch-type fastener adapted to be secured to thin panels comprising:

an axially rigid head and a shank being solid in transverse cross section; said head including a first circular flange; said head including a second circular flange; said first annular flange being between said second annular flange and said shank; said second annular flange being of smaller radial extent than said first circular flange and defining with said first circular flange an undercut circular groove;

said second circular flange having a concave end face defining a circular recess centrally disposed on said second circular flange on the side of said head opposite said shank to receive panel material displaced by said head during assembly of said fastener to a panel;

said undercut groove being disposed radially outwardly of said recess and concentric therewith;

said first circular flange including knurls tending to resist rotation of said fastener; and

said shank being externally threaded.

13. A one-piece clinch-type terminal adapted to be secured to thin panels comprising:

an axially rigid head and an elongated shank solid in transverse cross section but for a slot at the end opposite said head;

said head including a first annular flange;

said head including a second annular flange;

said first annular flange being between said second annular flange and said shank;

said second annular flange being of smaller radial extent than said first annular flange and defining with said first annular flange an undercut annular groove to receive panel material displaced by said head during assembly of said terminal to a panel; and

said second annular flange having a centrally recessed end face on the side of said head oppositesaid shank. 

1. In combination: a sheeted material or panel having first and second surfaces and a blind hole between said first and second surfaces; a fastener or the like including an axially rigid head and a shank; said head including a first annular flange; said head including a second annular flange of smaller radial extent than said first annular flange and defining with said first annular flange an undercut annular groove into which sheeted material is displaced by said first annular flange upon assembly to said sheeted material; said blind hole having an open end portion large enough to receive said second flange and having its opposite end portion closed by a part of said sheeted material to define a substantially planar closed end; and said head having a central recess juxtaposed with the part of said sheeted material closing said blind hole, the thickness of said sheet material being only slightly greater than the axial extent of said head.
 2. The structure set forth in claim 1 wherein said first annular flange includes means tending to resist rotation of said fastener.
 3. The structure recited in claim 1 wherein said shank is threaded.
 4. The structure recited in claim 1 wherein said shank is slotted.
 5. The structure recited in claim 2 wherein said means is a knurl.
 6. The structure recited in claim 2 wherein said means comprises forming said first annular flange of noncircular shape.
 7. In combination: a thin sheeted material or panel having first and second surfaces and a blind hole between said first and second surfaces; a fastener or the like including an axially rigid head and a shank; said head including an annular flange; said head including an annular pilot of smaller radial extent than said annular flange and defining with said annular flange an annular undercut groove into which sheeted material is displaced by said annular flange upon assembly to said sheeted material; said blind hole having an open end portion large enough to receive said pilot and having its opposite end portion closed by a thin part of said sheeted material; said head having a central recess juxtaposed with part of said sheeted material closing said blind hole; the thickness of said sheeted material being only slightly greater than the axial extent of said head; said annular flange including knurls on its outer periphery tending to resist rotation of said fastener; and said shank being threaded.
 8. A one-piece clinch-type fastener adapted to be secured to thin panels comprising: an axially rigid head and an externally threaded shank being solid in transverse cross section; said head including a first annular flange; said head including a second annular flange; said first annular flange being between said second annular flange and said shank; said second annular flange being of smaller radial extent than said first annular flange and defining with said first annular flange an undercut annular groove to receive panel material displaced by said head during assembly of said fastener to a panel and said second annular flange having a centrally recessed end face on the side of said head opposite said shank.
 9. The structure set forth in claim 8 wherein said first annular flange includes means tending to resist rotation of said fastener.
 10. The structure recited in claim 9 wherein said means is a knurl.
 11. The structure recited in claim 9 wherein said means is of noncircular shape.
 12. A one-piece clinch-type fastener adapted to be secured to thin panels comprising: an axially rigid head and a shank being solid in transverse cross section; said head including a first circular flange; said head including a second circular flange; said first annular flange being between said second annular flange and said shank; said second annular flange being of smaller radial extent than said first circular flange and defining with said first circular flange an undercut circular groove; said second circular flange having a concave end face defining a circular recess centrally disposed on said second circular flange on the side of said head opposite said shank to receive panel material displaced by said head during assembly of said fastener to a panel; said undercut groove being disposed radially outwardly of said recess and concentric therewith; said first circular flange including knurls tending to resist rotation of said fastener; and said shank being externally threaded.
 13. A one-piece clinch-type terminal adapted to be secured to thin panels comprising: an axially rigid head and an elongated shank solid in transverse cross section but for a slot at the end opposite said head; said head including a first annular flange; said head including a second annular flange; said first annular flange being between said second annular flange and said shank; said second annular flange being of smaller radial extent than said first annular flange and defining with said first annular flange an undercut annular groove to receive panel material displaced by said head during assembly of said terminal to a panel; and said second annular flange having a centrally recessed end face on the side of said head opposite said shank. 